Help Identifying Original Mopar Engine for Dodge D300

Hello everyone,

I have a Mopar engine in its original box that has never been opened and still retains its original seals and metal straps. The replacement engine was purchased around 1984 for a small Dodge D300 truck manufactured between 1970 and 1975. I do not want to break the original straps, so I need to identify the exact model of the engine without opening the box.

To help with identification, here are the box measurements and some technical data (box weight):

  • Box Measurements (converted to inches):
    • Length: 49 cm ≈ 19.3 inches
    • Width: 63 cm ≈ 24.8 inches
    • Height: 36 cm ≈ 14.2 inches
  • Technical Data (Box Weight):
    • Puncture Test: 1100 units
    • Combined Cladding Weight: 264 lbs per 1,000 ft²
    • Maximum Size: 120 inches
    • Gross Weight: 350 lbs
I would greatly appreciate any information, experiences, or suggestions that could help me determine the exact model of this Mopar engine.

Thanks in advance for your help!

Best regards,
D300 = One Ton Truck... Not Particularly "Small" likely Engine options, /6, 318, 360, 400, 440
19.3 x 24.8 x 14.2 Not very big not long enough to be a /6, not tall enough to be a big block
Gross Weight 350 lbs.... Not very heavy... Not heavy enough to be a long block...

My "guess" would be a 360 short block....

And yes, you need to open it... You don't know what you have & you don't know anything about it's condition..